MOTS-c: the mitochondria-derived peptide in the literature
Discovered in 2015, encoded by mitochondrial DNA, and studied primarily in animal models. Here's what the research actually shows.
TL;DR
- MOTS-c is a 16-amino-acid peptide encoded by the 12S rRNA gene in mitochondrial DNA — making it one of a newly recognized class of mitochondria-derived peptides.
- Published animal research documents AMPK activation, metabolic regulation, and exercise-capacity effects; human clinical data is very limited.
- FDA removed MOTS-c from Category 2 on April 22, 2026. As of September 14, 2026, it is not in any FDA 503A category and is not on the 503A bulks list.
What it is
MOTS-c (Mitochondrial Open Reading Frame of the 12S rRNA-c) is a peptide discovered by Lee et al. in 2015 and reported in Cell Metabolism. What makes it unusual is its origin: unlike most peptides encoded by nuclear DNA, MOTS-c is encoded by the mitochondrial genome — specifically within a reading frame of the 12S ribosomal RNA gene. Mitochondria are the energy-producing organelles in cells, and the discovery of peptides encoded by their genome opened a new area of research sometimes called mitochondrial endocrinology. MOTS-c is produced in mitochondria and can translocate to the nucleus, where, in cell studies, it appears to regulate gene expression in response to metabolic stress.
How it works
The primary mechanism identified in the Lee et al. discovery paper involves activation of AMPK — AMP-activated protein kinase, a cellular energy sensor that is activated when ATP levels fall. AMPK activation broadly shifts cellular metabolism toward fat oxidation, improves insulin sensitivity, and inhibits anabolic processes that consume ATP. In the original mouse studies, MOTS-c administration improved insulin sensitivity and reduced diet-induced obesity. Later research reported lower blood levels of MOTS-c in older people, positioning it as a potential marker of mitochondrial function and a candidate for study in age-related metabolic decline.
Who asks about it
MOTS-c comes up in mitochondrial health and longevity discussions, particularly among people who have encountered the concept of "mitokines" — peptides released by mitochondria that signal to other tissues. It also appears in exercise performance and metabolic optimization conversations. Its novelty — it's been known for barely a decade — makes it an area where understanding what we don't yet know is as important as understanding what we do.
What the research says
The foundational Lee et al. (2015) paper in Cell Metabolism remains the most-cited reference. In mouse models, MOTS-c injections reduced diet-induced insulin resistance. Human clinical trials are essentially absent from the literature; the compound has not progressed to Phase I safety evaluation in a published US trial context.
What to know
FDA removed MOTS-c from Category 2 on April 22, 2026, after its nomination was withdrawn. As of September 14, 2026, MOTS-c is not in any FDA 503A category and is not on the 503A bulks list. At its July 23–24, 2026 meeting, FDA's Pharmacy Compounding Advisory Committee voted to recommend adding MOTS-c to the Section 503A bulk drug substances list. The committee is advisory. As of September 14, 2026, FDA has not made a final decision. In February 2026, HHS Secretary Robert F. Kennedy Jr. said in a podcast interview that FDA would soon make more peptides accessible. That was not a formal proposal; the formal step was FDA's April 2026 change to its category list. Beyond the regulatory issue, the jump from mouse metabolic models to people involves enormous uncertainty: whether the mouse effects carry over to humans, and what the long-term effects would be, are unknown.
The Halftime POV
MOTS-c is at an early but genuinely interesting place in the longevity science arc. The discovery that mitochondria produce signaling peptides that regulate metabolism across tissues is a real scientific development — not hype. The honest position is that the human chapter of this story hasn't been written yet. When it is, we'll cover it.
Related reading:
FAQ
Q: What is MOTS-c? A: MOTS-c (Mitochondrial Open Reading Frame of the Twelve S rRNA-c) is a peptide encoded by mitochondrial DNA, first identified in 2015. It is a naturally occurring mitochondria-derived peptide (MDP). In cell and mouse studies, it acted as a metabolic regulator by activating AMPK pathways. Its discovery was described in Cell Metabolism by Lee et al. (2015).
Q: What does published research show about MOTS-c? A: Animal studies have documented effects on metabolic function, exercise capacity, and glucose regulation following MOTS-c administration. Lee et al. (2015) showed MOTS-c injection in mice improved insulin sensitivity and reduced diet-induced obesity. Human clinical trial data is sparse as of 2026. FDA removed MOTS-c from Category 2 on April 22, 2026. As of September 14, 2026, it is not in any FDA 503A category and is not on the 503A bulks list.
Q: What is MOTS-c's compounding status? A: FDA removed MOTS-c from Category 2 on April 22, 2026, after its nomination was withdrawn. As of September 14, 2026, MOTS-c is not in any FDA 503A category and is not on the 503A bulks list. At its July 23–24, 2026 meeting, FDA's Pharmacy Compounding Advisory Committee voted to recommend adding MOTS-c to the Section 503A bulk drug substances list. The committee is advisory. As of September 14, 2026, FDA has not made a final decision. In February 2026, HHS Secretary Robert F. Kennedy Jr. said in a podcast interview that FDA would soon make more peptides accessible. That was not a formal proposal; the formal step was FDA's April 2026 change to its category list. This page does not cover obtaining MOTS-c.
Disclaimer
MOTS-c was previously in FDA's Category 2. FDA removed it from Category 2 on April 22, 2026. As of September 14, 2026, it is not in any FDA 503A category and is not on the 503A bulks list. This article is educational and is not medical advice.
Sources
This article discusses compounds whose FDA compounding status has been under review (see our FDA categorization explainer). This article is provided for educational purposes only and does not constitute medical advice or an offer to sell.
Frequently asked questions
What is MOTS-c?
MOTS-c (Mitochondrial Open Reading Frame of the Twelve S rRNA-c) is a peptide encoded by mitochondrial DNA, first identified in 2015. It is a naturally occurring mitochondria-derived peptide (MDP). In cell and mouse studies, it acted as a metabolic regulator by activating AMPK pathways. Its discovery was described in Cell Metabolism by Lee et al. (2015).
What does published research show about MOTS-c?
Animal studies have documented effects on metabolic function, exercise capacity, and glucose regulation following MOTS-c administration. Lee et al. (2015) showed MOTS-c injection in mice improved insulin sensitivity and reduced diet-induced obesity. Human clinical trial data is sparse as of 2026. FDA removed MOTS-c from Category 2 on April 22, 2026. As of September 14, 2026, it is not in any FDA 503A category and is not on the 503A bulks list.
What is MOTS-c's compounding status?
FDA removed MOTS-c from Category 2 on April 22, 2026, after its nomination was withdrawn. As of September 14, 2026, MOTS-c is not in any FDA 503A category and is not on the 503A bulks list. At its July 23–24, 2026 meeting, FDA's Pharmacy Compounding Advisory Committee voted to recommend adding MOTS-c to the Section 503A bulk drug substances list. The committee is advisory. As of September 14, 2026, FDA has not made a final decision. In February 2026, HHS Secretary Robert F. Kennedy Jr. said in a podcast interview that FDA would soon make more peptides accessible. That was not a formal proposal; the formal step was FDA's April 2026 change to its category list. This page does not cover obtaining MOTS-c.
